是否始终启用USB电源？如果没有，如何编写驱动程序 [英] Is USB power always enabled ? And if not, how to write a driver

问题描述

我有一台带有交流电源适配器的设备，其中连接器是微型USB插头。但是，除非安装了特定的驱动程序，否则该设备似乎无法通过计算机的USB端口（使用标准的USB-mini USB电缆）供电。该驱动程序仅适用于Windows。我想通过不同平台上的USB插头为设备充电。

I have a device that came with an AC power adapter where the connector is a mini USB plug. The device however doesn't seem to power itself from a computer's USB port (using a standard USB-mini USB cable) unless a specific driver is installed. The driver is only available for Windows. I would like to charge the device from USB plugs on different platforms.

我的问题是：没有驱动程序，为什么电源无法进入设备？ USB端口开始供电是否总是需要驱动程序？抑或是专门为这种设备充电的设备，除非某些软件例程触发了它的充电操作？

My question is: why isn't power getting to the device without the driver? Is a driver always required for a USB port to start giving power? Or is it this device that's specifically made not to take a charge unless some software routine triggers it to do so?

我想我的问题可以概括为：电源不是吗？是否存在于USB电缆上，或者存在但设备忽略了它。如果答案是前者，我将尝试找出如何编写使电压始终存在的软件。

I guess my question can be summarized as: Is power not present on the USB cable or is it present but the device ignoring it. If the answer is the former, I'll be trying to figure out how to write software that will enable the voltage to always be present.

谢谢

推荐答案

没有驱动程序，为什么电源无法接通设备？

Why isn't power getting to the device without the driver?

计算机打开且USB控制软件未检测到当前透支时，USB端口始终通电。

USB ports are always powered when the computer is on and the USB control software hasn't detected current overdraw.

USB端口开始供电是否总是需要驱动程序吗？

Is a driver always required for a USB port to start giving power?

否，USB端口是总是需要先开始为设备供电，否则设备将永远无法启动连接。

No, the USB port is always required to start off providing power to the device, otherwise the device could never initiate a connection.

还是这台设备是专门制造的除非某些软件例程触发收费，否则不收费？

Or is it this device that's specifically made not to take a charge unless some software routine triggers it to do so?

这可能很复杂。为了满足USB规范，设备必须先向计算机注册，才能拉出几mA的电流。

This can be complex. To meet the USB spec a device cannot pull more than a few mA until it's registered with the computer.

但是，几乎每台计算机都允许USB端口拉出全部500mA的电流。 （及更多），然后关闭电源。

However, nearly every computer allows the USB port to pull the full 500mA (and more) before it'll shut the power off.

要充电的设备很不错，因为在计算机允许之前不要拉任何大功率的电源。

The device you're charging is being nice by not pulling any significant power until the computer gives permission.

编写软件将无济于事，该设备​​必须在USB总线上注册，最好由驱动程序完成。

Writing software won't help, the device has to register with the USB bus, which will best be done with the driver.

但是，插入式充电器不能执行此操作。可能已将USB插头的两条数据线短路在一起，这表明USB设备未连接到计算机，并且可以完全拉出500mA电流而无需等待。

However, the plug in charger doesn't do that. It likely has shorted the two data lines of the USB plug together, which signals the USB device that it's not connected to a computer and can pull the full 500mA without waiting.

拿起USB延长线，剪掉外套，然后将数据线（有时是绿色和黄色）一起短接到USB设备的一端，然后剪断而不会碰到PC的一端，然后离开

Take a USB extension cable, cut off the jacket, and short the data lines (green and yellow, sometimes) together on the end going to the USB device, and leave them cut without touching anything on the end going to the PC, and leave the read and black power wires connected through.

它可能起作用。如果没有，将墙壁充电器拆开，找出四根USB线各自的作用，然后看看是否可以复制。

It might work. If not, take the wall charger apart and find out what it's doing with each of the four USB wires, and see if you can duplicate that.

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